Google Inc. announced on Monday that Arthur Levinson, also a director at Apple Inc., has resigned from the company's board of directors.
The resignation of Levinson, who has been on the Google Board since April 2004, is effective immediately, the company said in a statement.
"Art has been a key part of Google's success these past five years, offering unvarnished advice and vital counsel on every big issue and opportunity Google has faced," said Google chief executive officer (CEO) and chairman Eric Schmidt, who himself quit Apple's board just two and a half months ago.
The search giant has not given the precise reason for the step-down of Levinson, while analysts believe the growing competition between the two companies is an obvious main cause. Levinson is one of Apple's two lead directors along with Bill Campbell, who is also an advisor to Google.
When consumers are still comparing iPhone and gPhone, Google has launched its plan for a personal computer operating system called Chrome that could race against Apple's product.
The smartphone business and software have put Google and Apple at a stance of competitors than collaborators.